Abstract

Paris Polyphylla var. yunnanensis (PPY) has been used in traditional medicine for the treatment of parotitis and abscess. Previous studies showed the quality of PPY was associated with cultivation years. In this study, we applied ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) and Fourier transform infrared (FT-IR) spectroscopy to measure the variation of saponins due to cultivation years in cultivated PPY. A rapid UHPLC–MS/MS method was developed for simultaneous determination of six major steroidal saponins (polyphyllin I, II, V, VI, VII and gracillin). Principal component analysis (PCA) was selected for pattern recognition of FT-IR profiles. The concentration of six targeted steroid saponins varied with the increase of cultivation year and attained the maximum level at 8th year (22.65 ± 1.65 mg g−1). A dynamic change with the growth of PPY presented in the content of diosgenin-type saponins and pennogenin-type saponins. After the treatment of standard normal variate (SNV), the PCA result showed that 4th and 5th years’ samples were solely classified into two parts and the chemical information of other samples was quite similar. According to FT-IR and UPLC-MS/MS results, an optimal harvest time recommend at 7th or 8th year in the current stage. These results could support the previous view that the variations of metabolites were associated with cultivation years and provided chemical evidence for further research on the agricultural practice of PPY.